Impact of Tongue Shapes on Hydraulic and Structure Performances of Double-Channel Pump Based on Fluid-Structure Interaction

2015 ◽  
Author(s):  
Binjuan Zhao ◽  
Jing Qiu ◽  
Huilong Chen ◽  
Yu Wang ◽  
Youfei Zhao
Keyword(s):  
Stress Concentration ◽  
Pressure Fluctuation ◽  
Maximum Stress ◽  
Fluid Structure Interaction ◽  
Radial Force ◽  
Vibration Velocity ◽  
Maximum Displacement ◽  
Structure Interaction ◽  
Corner Radius ◽  
Double Channel

The volute tongue has a great influence on the rotational impeller and stationary volute interaction in a pump. In this paper, the impact of tongue shapes on hydraulic and structural performances of a double channel pump with a specific speed of 110.9 is investigated, and four cases with different tongue shapes are simulated by the two-way coupling fluid-structure interaction (FSI) method. The result shows that, in the hydraulic performance aspect, the influence of tongue shapes on the efficiency is weak, and the maximum different value is 0.76%. But the maximum different value of pump-head is 0.126m. Tongue shapes mainly affect the pressure fluctuation in and after the tongue edge in the rotational direction. Pressure fluctuation near the rectangle tongue is stronger than that near the rounded tongue, and an appropriate increase of the corner radius will decrease the pressure fluctuation effectively. Because of the asymmetry of the volute, radial force on the volute is very large. It is periodical when the impeller rotates one circle and decreases obviously with an appropriate increase of the corner radius. Compared to the rounded tongue, the radial force on the volute with rectangle tongue is larger. In structural performance aspect, stress concentration of the impeller appears on the suction surface near the outlet, and the volute stress concentration appears near the tongue edge. Tongue shapes have little effect on the stress distribution of the impeller, but affect the volute stress deeply. The maximum stress near the rectangle tongue is a little larger than that near the rounded tongue, but an appropriate increase of the corner radius will decrease the maximum stress of volute obviously, and the amplitude will decrease slightly. Displacement with the magnitude 10−5 m happens in the pump, and the maximum displacement point appears in the outlet of the volute. It is periodical and mainly influenced by the blade-passing frequency. The tongue shape has little impact on the maximum displacement, but it has an obvious effect on the vibration velocity of the pump. Compared to the volute with rectangle tongue, the rounded tongue can decrease the vibration velocity, and larger corner radius can also suppress the vibration.

Numerical Study on Fluid Structure Interaction of Slug Flow in a Horizontal Pipeline

2016 ◽  
Vol 819 ◽  
pp. 319-325
Author(s):  
Abdalellah Omer Mohmmed ◽  
Mohammad Shakir Nasif ◽  
Hussain Hamoud Al-Kayiem ◽  
Zahid Ibrahim Al-Hashimy
Keyword(s):  
Slug Flow ◽  
Maximum Stress ◽  
Numerical Study ◽  
Fluid Dynamic ◽  
Fluid Structure Interaction ◽  
Water Velocity ◽  
Design Stage ◽  
Fluid Structure ◽  
Structure Interaction ◽  
Model Code

It is well-known that when slug flow occurs in pipes it may result in damaging the pipe line. Therefore it is important to predict the slug occurrence and its effect. Slug flow regime is unsteady in nature and the pipelines conveying it are indeed susceptible to significant cyclic stresses. In this work, a numerical study has been conducted to investigate the interaction between the slug flow and solid pipe. Fluid Structure Interaction (FSI) coupling between 3-D Computational Fluid Dynamic (CFD) and 3-D pipeline model code has been developed to assess the stresses on the pipe due to slug flow. Time – dependent stresses results has been analyzed together with the slug characteristic along the pipe. Results revealed that the dynamic behavior of the pipelines is strongly affected by slug parameters. The FSI simulation results show that the maximum stresses occurred close to the pipe supports due to slug flow, where the pipe response to the exerted slug forces is extremely high. These stresses will subsequently cause fatigue damage which is likely reduce the total lifetime of the pipeline. Therefore a careful attention should be made during the design stage of the pipeline to account for these stresses. The system has been investigated under multiple water velocities and constant air velocity, the maximum stress was obtained at the water velocity of 0.505 m/s. Moreover, when the water velocity is increased from 0.502 to 1.003 m/s the maximum stress magnitude is decreased by 1.2% and when it is increased to 1.505 m/s the maximum stress is diminished by 3.6%.

A Hybrid Model to Analyze the Fluid-Structure Interaction Phenomenon of a Relief System and Experimental Validation

2019 ◽  
Author(s):  
Feng Jie Zheng ◽  
Fu Zheng Qu ◽  
Xue Guan Song
Keyword(s):  
Hybrid Model ◽  
Pressure Fluctuation ◽  
Fluid Structure Interaction ◽  
Relief Valve ◽  
Fluid Structure ◽  
Structure Interaction ◽  
Model Combining ◽  
Valve Motion ◽  
Practical Engineering ◽  
Cfd Method

Abstract As one essential component of a pressurized system, a relief valve is used to guarantee the pressure within a prescribed range. But in practical engineering, pressure fluctuation caused by the operation of a relief valve will travel along the pipeline and couple with the motion of the valve, which might result in malfunction of the valve and the system. In order to investigate the fluid-structure interaction (FSI) phenomenon, a hybrid model combining the method of characteristics (MOC) and computational fluid dynamics (CFD) method is proposed. In the hybrid FSI model, the characteristics of pressure resource is modeled using the performance curves, the compressible gas transmitting in the pipe is calculated by one-dimensional MOC, and the air flow in the valve as well as the valve motion is simulated by a two-dimensional CFD model. To validate the hybrid model, 1:1 scaled test rig is conducted. The compared results show that the hybrid model not only can accurately capture the pressure fluctuation in straight pipeline induced by the closure of the valve but also can accurately predict the forms of the valve motion.

Numerical Investigations of the Long Blade Performance Using RANS Solution and FEA Method Coupled With One-Way and Two-Way Fluid-Structure Interaction Models

2017 ◽  
Author(s):  
Minyan Yin ◽  
Jun Li ◽  
Liming Song ◽  
Zhenping Feng
Keyword(s):  
Rotor Blade ◽  
Mechanical Performance ◽  
Fluid Structure Interaction ◽  
Interaction Model ◽  
Leading Edge ◽  
Von Mises Stress ◽  
Maximum Displacement ◽  
Fluid Structure ◽  
Structure Interaction ◽  
Von Mises

The aerodynamic and mechanical performance of the last stage was numerically investigated using three-dimensional Reynolds-Averaged Navier-Stokes (RANS) solution and Finite Element Analysis (FEA) coupled with the one-way and two-way fluid-structure interaction models in this work. The part-span damping snubber and tip damping shroud of the rotor blade and aerodynamic pressure on rotor blade mechanical performance was considered in the one-way model. The two-way fluid-structure interaction model coupled with the mesh deformation technology was conducted to analyze the aerodynamic and mechanical performance of the last stage rotor blade. One-way fluid-structure interaction model numerical results show that the location of nodal maximum displacement moves from leading edge of 85% blade span to the trailing edge of 85% blade span. The position of nodal maximum Von Mises stress is still located at the first tooth upper surface near the leading edge at the blade root of pressure side. The two-way fluid-structure interaction model results show that the variation of static pressure distribution on long blade surface is mostly concentrated at upper region, absolute outflow angle of long blade between the 40% span and 95% span reduces, the location of nodal maximum displacement appears at the trailing edge of 85% blade span. Furthermore, the position of nodal maximum Von Mises stress remains the same and the value decreases compared to the oneway fluid-structure model results.

FSI Analysis of Flow-Induced Vibration in Subsea Jumper Subject to Downstream Slug and Ocean Current

2014 ◽  
Author(s):  
Yaojun Lu ◽  
Chun Liang ◽  
Juan J. Manzano-Ruiz ◽  
Kalyana Janardhanan ◽  
Yeong-Yan Perng
Keyword(s):  
Pressure Fluctuation ◽  
Interaction Analysis ◽  
Dominant Role ◽  
Fluid Structure Interaction ◽  
Vibration Response ◽  
Dynamics Simulation ◽  
Ocean Current ◽  
Flow Induced Vibration ◽  
Fluid Structure ◽  
Structure Interaction

This paper presents a multiphysics approach for characterizing flow-induced vibrations in a subsea jumper subject to pressure fluctuation due to downstream slugging and external vortex shedding effects due to ocean current. In this study the associated fluid properties, phase behavior, and slugging dynamics were all characterized at subsea condition using PVTSIM and OLGA programs, respectively; the outcomes were then applied to a two-way fluid-structure interaction analysis (FSI) to quantify the vibration response. To mitigate the resonant phenomenon, detailed modal analysis was also conducted to check the modal shapes and natural frequencies. Therefore, this study integrated the best practices in flow assurance study (OLGA and PVTSim), computational fluid dynamics simulation (CFD), and computational structure analysis (FEA), and provided a complete solution to the fluid-structure interaction involved in a subsea jumper. It is revealed that both the slugging flow and the external ocean current induce vibration response in a subsea jumper. Compared to the vortex-induced vibration due to the external current and the flow-induced vibration due to the internal flow, the pressure fluctuation due to the slug plays a dominant role in generating excessive vibration and fatigue failure of a subsea jumper. Although this study focused on a subsea jumper only, the same approach can be applied to subsea flowline, subsea riser, and other subsea structures.

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